全文获取类型
收费全文 | 1448篇 |
免费 | 91篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 18篇 |
妇产科学 | 18篇 |
基础医学 | 205篇 |
口腔科学 | 17篇 |
临床医学 | 179篇 |
内科学 | 308篇 |
皮肤病学 | 14篇 |
神经病学 | 236篇 |
特种医学 | 50篇 |
外科学 | 191篇 |
综合类 | 6篇 |
预防医学 | 46篇 |
眼科学 | 26篇 |
药学 | 98篇 |
中国医学 | 1篇 |
肿瘤学 | 129篇 |
出版年
2023年 | 9篇 |
2022年 | 23篇 |
2021年 | 46篇 |
2020年 | 20篇 |
2019年 | 26篇 |
2018年 | 42篇 |
2017年 | 37篇 |
2016年 | 46篇 |
2015年 | 49篇 |
2014年 | 64篇 |
2013年 | 69篇 |
2012年 | 96篇 |
2011年 | 116篇 |
2010年 | 65篇 |
2009年 | 59篇 |
2008年 | 101篇 |
2007年 | 82篇 |
2006年 | 93篇 |
2005年 | 84篇 |
2004年 | 98篇 |
2003年 | 84篇 |
2002年 | 58篇 |
2001年 | 20篇 |
2000年 | 8篇 |
1999年 | 15篇 |
1998年 | 16篇 |
1997年 | 10篇 |
1996年 | 14篇 |
1995年 | 6篇 |
1994年 | 12篇 |
1993年 | 10篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1973年 | 2篇 |
1932年 | 2篇 |
1911年 | 1篇 |
1910年 | 1篇 |
排序方式: 共有1556条查询结果,搜索用时 0 毫秒
61.
Sellitto A Galizia G De Fanis U Lieto E Zamboli A Orditura M De Vita F Giunta R Lucivero G Romano C 《Journal of clinical immunology》2011,31(6):1095-1104
CD4+CD25+Foxp3+ regulatory T cells (Treg) specialize in suppressing immune responses. In this study, 47 consecutive colon
cancer patients were subjected to circulating Treg frequency assessment by flow cytometry before and after cancer resection.
Thirty-two healthy subjects served as controls. Circulating Treg frequencies were significantly higher in colon cancer patients
with respect to healthy controls. When patients were subgrouped according to Dukes stages, a linear relationship was observed
between Dukes stages and Treg frequencies. In radically resected patients, Treg frequencies were shown to have significantly
dropped down. Patients with advanced colon cancer were more likely to have significantly higher proportions of circulating
Treg frequencies than Dukes A and B patients when compared to healthy subjects. Of note, nonradically resected patients were
found to display reductions in—but not normalization of—Treg frequencies. These results suggest that cancer itself may be
able to drive Treg recruitment as a strategy of immunoevasion. 相似文献
62.
Claudia Santoro Simona Riccio Federica Palladino Ferdinando Aliberti Marco Carotenuto Mariateresa Zanobio Cristina Peduto Vincenzo Nigro Silverio Perrotta Giulio Piluso 《European journal of medical genetics》2021,64(5):104190
Concurrence of distinct genetic conditions in the same patient is not rare. Several cases involving neurofibromatosis type 1 (NF1) have recently been reported, indicating the need for more extensive molecular analysis when phenotypic features cannot be explained by a single gene mutation. Here, we describe the clinical presentation of a boy with a typical NF1 microdeletion syndrome complicated by cleft palate and other dysmorphic features, hypoplasia of corpus callosum, and partial bicoronal craniosynostosis caused by a novel 2bp deletion in exon 2 of Meis homeobox 2 gene (MEIS2) inherited from the mildly affected father. This is only the second case of an inherited MEIS2 intragenic mutation reported to date. MEIS2 is known to be associated with cleft palate, intellectual disability, heart defects, and dysmorphic features. Our clinical report suggests that this gene may also have a role in cranial morphogenesis in humans, as previously observed in animal models. 相似文献
63.
Alberto Biondi Roberto Persiani Ferdinando Cananzi Marco Zoccali Vincenzo Vigorita Andrea Tufo Domenico D��Ugo 《World journal of gastroenterology : WJG》2010,16(27):3358-3370
Gastric carcinoma is one of the most frequent malignancies in the world and its clinical behavior especially depends on the metastatic potential of the tumor.In particular,lymphatic metastasis is one of the main predictors of tumor recurrence and survival,and current pathological staging systems reflect the concept that lymphatic spread is the most relevant prognostic factor in patients undergoing curative resection.This is compounded by the observation that two-thirds of gastric cancer in the Western world... 相似文献
64.
The purpose of this study was to investigate how the ocular surface area (OSA) and the eye blink frequency (BF) are affected
by a high versus a low-monitor position during visual display unit (VDU) work with varying cognitive demands. In a balanced
randomized (2 × 2) design ten healthy subjects (five males, five females) completed two different tasks on the VDU in a simulated
office environment (23°C and 30–35% relative humidity); an active task with demands on vision and hand-eye coordination, and
a passive task. Two monitor positions were used: high (the monitors’ upper edge at the same height as the subjects’ eyes)
and low (lowered by 25° and perpendicular to gaze angle). Each task lasted 10 min. An OSA-proxy was measured from video recordings,
and BF was sampled by electrooculography. The effect of lowering the gaze angle by 25° decreased the OSA-proxy significantly
(P < 0.01) during the active task, indicating that a low position of the monitor may be preferable even though the BF also decreased.
Overall, the OSA-proxy was 6% higher during the active task compared to the passive while BF during the active task was 69%
lower than during the passive task. The low BF during the active task was succeded by a burst with high BF after cessation
of the active task, indicating a compensatory blinking process. This stresses that interchange of work tasks with different
cognitive load is as important as the monitor position in the prevention of visual and musculoskeletal disorders. 相似文献
65.
Nicoletti F Di Marco R Papaccio G Conget I Gomis R Bernardini R Sims JE Shoenfeld Y Bendtzen K 《European journal of immunology》2003,33(8):2278-2286
IL-18 is a cytokine structurally and functionally related to IL-1 that, in synergy with IL-12, stimulates the synthesis of IFN-gamma from T lymphocytes and natural killer cells. Because IFN-gamma plays a key pathogenic role in the development of murine immunoinflammatory diabetes induced by multiple low doses of streptozotocin (STZ) we investigated the effect of negating the actions of endogenous IL-18 in this model by administering recombinant IL-18-binding protein:Fc (IL-18 bp:Fc). C57BL/6 mice were injected once daily with 40 mg/kg STZ for 5 consecutive days, day 0 being the first day of STZ challenge. Relative to control animals treated in parallel with either PBS or human IgG, mice treated from day -3 to day 7 with daily doses of 150 microg of IL-18 bp:Fc exhibited lower incidence of diabetes and milder insulitis. In contrast, mice that were treated with IL-18 bp:Fc from day 7 to day 14 exhibited clinical and histological signs of STZ-induced diabetes similar to those of control mice treated with IgG. The protective effect of IL-18 bp:Fc was accompanied by modified ex vivo immune responses, in that spleen cells and peritoneal macrophages contained fewer IFN-gamma secreting cells and released lower amounts of nitrite (an index of nitric oxide production) and IL-1beta. We conclude that intact IL-18 function is essential for the full diabetogenic effect of low dose STZ in C57BL/6 mice. 相似文献
66.
Serum Interferon (IFN)-Neutralizing Antibodies and Bioactivities of IFNs in Patients with Severe Type II Essential Mixed Cryoglobulinemia 下载免费PDF全文
Carolina Scagnolari Milvia Casato Francesca Bellomi Francesca De Pisa Ombretta Turriziani Rossella Coviello Maria Rosaria Pirro Ferdinando Dianzani Guido Antonelli 《Clinical and Vaccine Immunology : CVI》2003,10(1):70-77
The efficacy of alpha interferon (IFN-α) in the treatment of severe type II essential mixed cryoglobulinemia (EMC) has been reported previously. In some patients, the development of neutralizing antibodies to recombinant IFN-α (rIFN-α) can affect the clinical response achieved with rIFN-α; a second treatment with natural IFN-α preparations may reinduce the clinical response. In the present study the ability of leukocyte IFN (LeIFN) to restore the response was investigated from a pharmacodynamic viewpoint. Specifically, the pharmacodynamic profiles of different IFN-α preparations were studied by measuring the serum neopterin levels and the levels of expression of protein MxA mRNA in in vivo peripheral blood mononuclear cells in two patients with EMC whose resistance to rIFN-α2a treatment increased concomitantly with the development of neutralizing antibodies. These markers were measured before injection and at 24 and 48 h after a single injection of rIFN-α2a, consensus IFN [(C)IFN], or LeIFN. No increase or only a slight increase in MxA mRNA levels was detectable after administration of rIFN-α2a or (C)IFN, whereas a significant increase (≥10-fold) in MxA mRNA expression was recorded following administration of LeIFN. The neutralizing antibodies to rIFN-α2a cross-react with (C)IFN. Sera from these patients neutralized most but not all of the subtypes present in the natural IFN-α (LeIFN) mixture, and no significant increase in neopterin levels was observed after these patients were switched to LeIFN treatment. In summary, the data demonstrate that the problem of neutralizing antibodies still exists and that LeIFN may induce an increase in the level of MxA mRNA expression but not an increase in neopterin levels in patients who are resistant to treatment with rIFN-α2a or (C)IFN. 相似文献
67.
Immunohistochemical expression of p16(INK4a) is predictive of HR-HPV infection in cervical low-grade lesions. 总被引:3,自引:0,他引:3
Maria Benevolo Marcella Mottolese Ferdinando Marandino Giuseppe Vocaturo Roberto Sindico Giulia Piperno Luciano Mariani Isabella Sperduti Paola Canalini Raffaele P Donnorso Amina Vocaturo 《Modern pathology》2006,19(3):384-391
The p16(INK4a) is a cyclin-dependent kinase inhibitor that decelerates the cell cycle by inactivating the cyclin-dependent kinases involved in the phosphorylation of the retinoblastoma protein (RB). Expression of E6 and E7 oncogenes of high-risk (HR) human papillomavirus (HPV), affecting the RB-p16 pathway, leads to p16 upregulation. Although it is widely reported that p16 is overexpressed in a high percentage of preneoplastic lesions and in almost all carcinomas of the uterine cervix, protein upregulation and its correlation with HPV infection in low-grade lesions is still being debated. In this study, we investigated in parallel, p16 expression and HPV infection in 100 cervical biopsies (17 normal tissues, 54 CIN1, 10 CIN2, 11 CIN3, eight invasive squamous cancers). Results obtained demonstrated that none of the 17 normal cervical tissues, evaluated by immunohistochemistry, presented p16 positivity whereas, starting from CIN1 (31%) to CIN2 (90%), CIN3 (100%) and carcinomas (100%), a constant and significant increase of protein overexpression (P<0.0001) was observed. In addition, p16 overexpression consistently showed elevated sensitivity (84%) and specificity (98%) in detecting HR-HPV infection with a high positive predictive value (97%) and negative predictive value (86%). Of interest, 93% of the p16-positive CIN1 were also HR-HPV infected. Our findings confirmed that p16 overexpression is associated to high-grade precancerous lesions and cervical carcinomas, and further demonstrated that immunohistochemical evaluation of p16 may be a useful biomarker in identifying HR-HPV-infected low-grade lesions. 相似文献
68.
Ferdinando Iellamo Marco Di Rienzo Daniela Lucini Jacopo M. Legramante Paolo Pizzinelli Paolo Castiglioni Fabio Pigozzi Massimo Pagani Gianfranco Parati 《The Journal of physiology》2006,572(3):829-838
One of the most important features of prolonged weightlessness is a progressive impairment of muscular function with a consequent decrease in exercise capacity. We tested the hypothesis that the impairment in musculo-skeletal function that occurs in microgravity results in a potentiation of the muscle metaboreflex mechanism and also affects baroreflex modulation of heart rate (HR) during exercise. Four astronauts participating in the 16 day Columbia shuttle mission (STS-107) were studied 72–71 days before launch and on days 12–13 in-flight. The protocol consisted of 6 min bicycle exercise at 50% of individual followed by 4 min of postexercise leg circulatory occlusion (PECO). At rest, systolic (S) and diastolic (D) blood pressure (BP), R-R interval and baroreflex sensitivity (BRS) did not differ significantly between pre- and in-flight measurements. Both pre- and in-flight, SBP increased and R-R interval and BRS decreased during exercise, whereas DBP did not change. During PECO preflight, SBP and DBP were higher than at rest, whereas R-R interval and BRS recovered to resting levels. During PECO in-flight, SBP and DBP were significantly higher whereas R-R interval and BRS remained significantly lower than at rest. The part of the SBP response (Δ) that was maintained by PECO was significantly greater during spaceflight than before (34.5 ± 8.8 versus 13.8 ± 11.9 mmHg, P = 0.03). The tachycardic response to PECO was also significantly greater during spaceflight than preflight (−141.5 ± 25.2 versus −90.5 ± 33.3 ms, P = 0.02). This study suggests that the muscle metaboreflex is enhanced during dynamic exercise in space and that the potentiation of the muscle metaboreflex affects the vagally mediated arterial baroreflex contribution to HR control. 相似文献
69.
Botti M Minelli LB Gazza F Ragionieri L Acone F Panu R Palmieri G 《The anatomical record. Part A, Discoveries in molecular, cellular, and evolutionary biology》2006,288(10):1050-1058
The location of sensory, somatic, and autonomic neurons projecting to the pig cremaster muscle (CM) was studied by means of the retrograde neuronal tracer Fast Blue (FB) technique. FB was randomly injected in the left CM of four impuberal pigs and serial sections of sensory and autonomic ganglia and spinal cord were examined under a fluorescence microscope. Additionally, some indications about the number and size of labeled neurons were given. Sensory pseudounipolar somata were located ipsilaterally in the L2-L6 and S1-S2 dorsal root ganglia, their total number ranging between 125 and 194, their mean diameter between 24 and 89 microm. Somatic multipolar motoneurons were located ipsilaterally in the L2-L4 neuromeres of the spinal cord, their total number ranging between 53 and 169, their mean diameter between 29 and 53 microm. Autonomic multipolar paravertebral ganglia neurons were located ipsilaterally from L1 to S4 and contralaterally from L2 to S2. Their total number ranged from 2,015 to 3,067 and their mean diameter between 25 and 55 microm. The multipolar caudal mesenteric ganglia neurons were located bilaterally, their total number ranging between 14 and 1,408 and their diameter from 22 to 39 microm. In two subjects only, multipolar neurons were also found ipsilaterally in the microganglia of pelvic plexus (2 and 13 neurons). Their mean diameter ranged between 28 and 54 microm. Our study documented that the CM-projecting neurons were located at different neural levels, with a predominance in the autonomic ganglia. 相似文献
70.
Ferdinando Iellamo Jacopo Maria Legramante Filippo Castrucci Michele Massaro Gianfranco Raimondi Giuseppe Peruzzi Giuseppe Tallarida 《European journal of applied physiology》1993,66(5):381-387
Summary In recent studies in humans the role of cardiopulmonary baroreflexes in modulating the cardiovascular responses to isometric exercise (somatic pressor reflex) has been investigated by performing static hand-grip exercise during deactivation of cardiopulmonary receptors produced by low levels of lower body negative pressure; however, findings from these studies have not been consistent. The purpose of this study was to investigate whether a more physiological unloading stimulus of cardiopulmonary baroreceptors, obtained by sequentially changing posture, could influence the pressor response to somatic afferent stimulation induced by isometric, exercise. To accomplish this, ten healthy subjects performed a 2-min isometric handgrip (IHG) at 30% maximal voluntary contraction after 10 min of supine rest and, in rapid sequence, after 10 min of sitting and 10 min of standing, at the time when, owing to their transitory nature, the cardiovascular effects, due to arterial baroreceptor intervention should have been minimal. During IHG arterial pressure (BPa) was continuously and noninvasively measured to quantify accurately the blood pressure response to IHG both in magnitude and time course. Results showed that the pressor response to IHG was not significantly influenced by change in posture, either in magnitude or in time course. The mean arterial pressure increased by 17.4 (SEM 2.5), 18.6 (SEM 1.2) and 17.0 (SEM 1.3) mmHg in supine, sitting and standing [2.3 (SEM 0.3), 2.5 (SEM 0.2) and 2.3 (SEM 0.2) kPa] positions, respectively. Also the heart rate response to IHG was unaffected by change in posture. Most important, the sum of the separate BPa responses induced by supine IHG and by posture change from supine to sitting (summation of reflexes) was not significantly different from the pressor response observed during sitting IHG (interaction of reflexes). Likewise, the sum of the separate BPa. responses induced by sitting IHG and by changing postures from sitting to standing was not significantly different from the pressor response to standing IHG. These data indicate that, under physiological conditions, cardiopulmonary baroreflexes do not exert a significant role in modulating the reflex pressor drive from muscles during isometric exercise in healthy humans. 相似文献